A man who facilitated the production of child pornography involving his own daughter which her mother filmed, has had his prison sentence reduced on appeal.

The man, who cannot be identified for legal reasons, had pleaded not guilty at Dublin Circuit Criminal Court to sexual exploitation and to knowingly causing or facilitating the production of child pornography in Dublin between 2009 and 2010.

He was sentenced to five years imprisonment with the final 12 months suspended by Judge Sarah Berkeley on July 31, 2014. Separately, the girl's mother was sentenced to 36 months with the final 20 suspended on a plea of guilty.

The man successfully appealed against the severity of his sentence today with the Court of Appeal holding that the trial judge failed to give appropriate weight to the mitigating factors and erred in giving sufficient discount for his remorse.

Accordingly, he was resentenced to three-and-a-half years imprisonment with the final 12 months suspended.

His barrister, Patrick Gageby SC, had told three-judge court that his client's ex-partner was the instigator of the offence “for reasons which pass human understanding”.

However, his client got a sentence “three times that” of his ex-partner, who had not fought the case, Mr Gageby submitted.

Counsel further submitted that the judge erred in holding that his client had no remorse.

Giving judgment, Mr Justice John Edwards said a member of the public had found a mobile phone crushed on the road in June 2010 and amongst its remnants was an SD card which appeared to be undamaged.

The member of the public had intended to make use of the SD card himself, Mr Justice Edwards said. However, when he inserted the SD card into his own mobile phone he found disturbing images stored of an ostensibly sexual nature involving an adult and a very young child.

The member of the public recognised the child, who was living in his locality, and immediately went to a nearby garda station, Mr Justice Edwards said.

The gardaí commenced an immediate criminal investigation and confirmed that the child was the man's four-year-old daughter.

An interim care order was successfully sought by the HSE the following day. The man and his ex-partner were both in attendance for the interim care order hearing, Mr Justice Edwards said.

Mr Justice Edwards said the trial judge erred in not giving sufficient discount for the man's remorse.

The trial judge also erred in failing to attribute appropriate weight to the mitigating factors that she identified such as his previous good character, his cooperation with gardaí and his low level of intelligence which meant he was more susceptible to bullying in prison.

He said incentivising rehabilitation was essential and the suspension of the final 12 months of his five year sentence was not sufficient in itself to cater for the mitigating factors.

Mr Justice Edwards, who sat with Mr Justice George Birmingham and Mr Justice Garrett Sheehan, resentenced him to three and a half years with the final 12 months suspended.